Revenue - Schedule of Cumulative Effect of Changes Made to Consolidated Balance Sheet for Adoption of New Revenue Standard (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Assets
Accounts receivables, net	$ 133,895		$ 120,553
Inventories	68,803		32,740
Prepaid expenses and other current assets	13,867		11,367
Deferred cost of revenue, current portion	1,504		3,007
Deferred cost of revenue, non-current portion			5,403
Other non-current assets	4,305		3,429
Liabilities:
Accounts payable and accrued liabilities	147,255		128,757
Deferred revenue, current portion	38,543	$ 42,950	34,501
Deferred revenue, non-current portion	13,376	12,023	48,511
Equity:
Accumulated deficit	(260,674)		$ (283,338)
Accounting Standards Update 2014-09
Assets
Accounts receivables, net		133,281
Inventories		32,632
Prepaid expenses and other current assets		15,480
Deferred cost of revenue, current portion		1,931
Deferred cost of revenue, non-current portion		1,518
Other non-current assets		3,207
Liabilities:
Accounts payable and accrued liabilities		130,007
Deferred revenue, current portion		42,950
Deferred revenue, non-current portion		12,023
Equity:
Accumulated deficit		(244,999)
Accounting Standards Update 2014-09 | Adjustment on Adoption of New Revenue Standard
Assets
Accounts receivables, net	18,472	12,728
Inventories		(108)
Prepaid expenses and other current assets	2,864	4,113
Deferred cost of revenue, current portion	(2,459)	(1,076)
Deferred cost of revenue, non-current portion	(5,309)	(3,885)
Other non-current assets		(222)
Liabilities:
Accounts payable and accrued liabilities	2,000	1,250
Deferred revenue, current portion	4,384	8,449
Deferred revenue, non-current portion	(33,784)	(36,488)
Equity:
Accumulated deficit	$ 40,968	$ 38,339